1. Field of the Invention
The present invention relates to a wireless communication system that uses a plurality of frequency blocks. The wireless communication system can support at least one of single carrier-frequency division multiple access (SC-FDMA), multi carrier-frequency division multiple access (MC-FDMA), and orthogonal frequency division multiple access (OFDMA). The wireless communication system can also support at least one of frequency division duplex (FDD), half-FDD (H-FDD), and time division duplex (TDD). More particularly, the present invention relates to a method of signaling control information in the wireless communication system.
2. Background Art
FIG. 1A illustrates a network structure of an Evolved Universal Mobile Telecommunications System (E-UMTS). The E-UMTS system is an evolved version of the conventional WCDMA UMTS system and standardization thereof is in progress under the 3rd Generation Partnership Project (3GPP). The E-UMTS is also referred to as a Long Term Evolution (LTE) system. For details of the technical specifications of the UMTS and E-UMTS, refer to Release 7 and Release 8 of “3rd Generation Partnership Project; Technical Specification Group Radio Access Network”.
Referring to FIG. 1A, the E-UMTS includes a User Equipment (UE), a base station, and an Access Gateway (AG) which is located at an end of a network (E-UTRAN) and connected to an external network. Generally, the base station can simultaneously transmit multiple data streams for a broadcast service, a multicast service and/or a unicast service. The AG can be divided into a part that handles processing of user traffic and a part that handles control traffic. In this case, the AG part for processing new user traffic and the AG part for processing control traffic can communicate with each other using a new interface. One or more cells may exist for one eNode B (eNB). One cell constituting eNB is set to one of bandwidths of 1.25, 2.5, 5, 10, and 20 Mhz to provide a downlink or uplink transport service to several user equipments. Also, in a wireless communication system, one base station controls data transmission and reception for a plurality of user equipments. The base station transmits downlink scheduling information of downlink data to the corresponding user equipment to notify time and frequency domains to which data will be transmitted and information related to encoding scheme, data size, hybrid automatic repeat and request (HARQ). Also, the base station transmits uplink scheduling information of uplink data to the corresponding user equipment to notify time and frequency domains that can be used by the corresponding user equipment, and information related to encoding scheme, data size, HARQ. Different cell can be established to provide different bandwidths. An interface for transmitting user traffic or control traffic can be used between eNBs. A Core Network (CN) may include the AG and a network node or the like for user registration of the UE. An interface for discriminating between the E-UTRAN and the CN can be used. The AG manages mobility of a UE on a Tracking Area (TA) basis. One TA includes a plurality of cells. When the UE has moved from a specific TA to another TA, the UE notifies the AG that the TA where the UE is located has been changed.
FIG. 1B illustrates a network structure of an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) system. The E-UTRAN system is an evolved version of the conventional UTRAN system. The E-UTRAN includes base stations that will also be referred to as “eNode B” or “eNB”. The eNBs are connected with each other through an X2 interface. X2 user plane interface (X2-U) is defined between the eNBs. The X2-U interface provides non-guaranteed delivery of a user plane PDU. X2 control plane interface (X2-CP) is defined between two neighboring eNBs. The X2-CP performs context transfer between eNBs, control of a user plane tunnel between a source eNB and a target eNB, transfer of handover message, and uplink load management. The eNB is connected to the User Equipment (UE) through a radio interface and is connected to an Evolved Packet Core (EPC) through a S1 interface. S1 user plane interface (SI-U) is defined between the eNB and a serving gateway (S-GW). S1 control plane interface is defined between the eNB and a mobility management entity (MME). The S1 interface performs bearer service management of an evolved packet system (EPS), non-access stratum (NAS) signaling transport, network sharing, MME load balancing, etc.